流体处于层流状态时，其流速（）临界速度。

管内流体的雷诺数小于（）时，流体处于层流状态。

层流底层

流体在圆管中流动时，由层流变为紊流时的临界流速比由紊流时变为层流时的临界流速（）。

流体在直管内作层流流动时，其流体阻力与流体的性质、管径、管长有关，而与管子的粗糙度无关。

流体在直管中流动，当（）≤2000时，流体的流动类型属于层流。

Every deliberate act of wrongdoing by the master or any of the crew against the ship or cargo，without the authorization or privity of the Shipowner or his agent，is（）.

（）, or drum is used for hauling in or letting out the wires or ropes which will fasten the ship to the shore.

A salvor may be（）the whole or part of the payment due under Salvage Convention to the extent that the salvage operations have become necessary or more difficult because of fault or neglect on his part or if the salvor has been guilty of fraud or other dishonest conduct.

流体在圆形管道中流动，无论层流或紊流，管壁处流体速度均为零。

逻辑运算符（AND、NOT、OR）的运算顺序是AND→OR→NOT。

逻辑运算符（AND、NOT、OR）的运算顺序是AND→OR→NOT。